No member whose shares are pledged or whose account is pledged as security for a real estate loan from the association issuing such shares or accepting such account shall be permitted to make a withdrawal or be entitled to give any valid notice of intention to withdraw in respect of such shares or account until the indebtedness for which such shares are pledged or for which such account is pledged as security has been fully paid; except that withdrawals may be made without notice if the full amount of such withdrawals is used to pay such indebtedness or any part thereof.